This discussion thread is related to my question.
A solution that seems to work for single line Latex commands is to use the in-buffer setting #+LATEX.
In the example mentioned in the question, we would have:
Which correctly exports to:
The answer to my problem was a comment from The_Blackbeard user at reddit.
Have you taken into account that while emacs-lisp-mode derives from prog-mode, tex-mode derives from text-mode?
Once I had that information the rest was easy to fix.
The line "The following pre" is the first line of its paragraph (it's the only line of its paragraph), and is thus indented. Try a longer paragraph before the source block to see that it does match the indentation of the subsequent lines of the paragraph, just not the first one.
If you don't want the first line of the paragraph indented change it to: